12. Android userspace (bridge to the firmware)

Everything else in this documentation set stops at the Android userspace boundary: the boot chain, the SoC fabric, the secure world and the DSP/PIL images are all described up to the point where the Linux kernel hands off to init and the system / vendor partitions take over. This section deliberately crosses that line, for the userspace layers that are continuous with the below-userspace work and cannot be understood without it — except the peripheral-hardware slices (e-ink/pen, wireless, sensors, audio), which each now live next to their own hardware section instead of here:

  • the firmware-blob inventory — the actual payload files that the below-userspace loaders (TZ/PAS, the kernel PIL/subsys framework, the in-kernel driver firmware requests) authenticate and load. Below userspace we documented the loaders; this locates the bits they load;

  • the vendor drivers and HALs — the loadable kernel modules and HAL services that bind the SoC blocks in SoC platform fabric to Android, and don’t belong to a single peripheral domain (audio/wireless/sensors/display each have their own hal page now — see Audio drivers and HAL, Wireless drivers and HAL, Sensor drivers and HAL, Display drivers and HAL);

  • the security and DRM userspace — the keystore/keymaster, storage encryption, DRM and biometric clients that depend on the secure world in Secure world and coprocessors (TZ, HYP, trustlets); and

  • the platform userspace — the Onyx/Boox framework customisation, the init/SELinux/A-B boot machinery, and the preinstalled-app / GMS audit, to the extent each touches the hardware or the boot chain.

Everything here is static, read out of the extracted partition images (artifacts/super/*.img), the raw firmware-bearing partitions (_READONLY/lun4/*.bin), the decompressed kernel Image (artifacts/kernel) and its kernel_config.txt. No code was executed and nothing was run on a device. Pure-AOSP internals that are unchanged from stock Android are described only where they touch the hardware bridge or the boot chain — this is not a general Android teardown. (On the version split — an Android-15 system over an Android-11 vendor on a 4.19 kernel — see The Onyx/Boox platform layer.)